This invention relates to the field of installing ground rods into the earth. Ground rods are commonly used in association with utility poles so as to prevent damage caused by lightening, large electrical surges, stray voltages and the like. Ground rods are extremely elongated, narrow rods of high density conductive metal or other core conductive metal. They commonly come in eight foot lengths and are installed into the earth in the vicinity of the utility pole during installation of the utility pole. Quite often ground rods are interconnected using couplers and driven 7 to 16 feet into the earth depending on whether hard rock may be encountered. Upon installation, the ground rod is physically connected to the utility pole by electrically conductive wire.
Installation of these ground rods has customarily been by a number of methods, including impacting devices that repeatedly hammer one end of the rod. Impacting devices are somewhat cumbersome, particularly compared to the invention herein. Impacting also tends to more easily cause the rod to bend and deform.
Another method often used is drilling or boring. However, as will be seen, such method is time consuming compared to the invention herein.
Other drivers, pushers and impacters, and methods using them, may be time consuming, expensive, cumbersome, and the devices themselves are often complicated.
What is needed is a simple, efficient and effective device using the equipment commonly available during installation of utility poles and the like, and that is also economical to build and use, and it is to these objectives the present invention is directed.
As will be seen, during installation of utility poles, and most instances a common drilling rig is on site that would have been used for drilling the utility pole hole. A very common device attached to these drilling rigs is a Kelly Bar to which many drilling attachments, such as the drill itself, are removabley attached.
Consequently the present invention is directed toward its attachability to a Kelly Bar or the like using a pin attachment to a plunger. Two additional telescoping pieces slidably connected to the plunger having what are commonly referred to as "dogs" to hold the telescoping pipes together when extended. The device, upon being installed on the Kelly Bar, is raised above the location where the ground rod is to be inserted, the ground rod is then inserted into the Kelly Bar and the Kelly Bar is then lowered which then lowers the plunger (connected to the Kelly Bar) through the telescoping members, preferably aluminum. The significant forces of the hydraulic pressures available force the ground rod device into the earth. The telescoping devices help maintain the stability of the rod so as to prevent bending of the rod. The drill operator can normally feel when the device has hit rock, and if it has not, the device can be lifted, a coupler added to the rod, another rod added and continued to be driven down into the earth by repeating the process. The plunging or driving process takes only a few seconds and the entire process, including moving the drill bit and placing the invention on the Kelly Bar, takes only a matter of minutes.
The installation device itself, as will be seen, is easy and inexpensive to build, easy to use and effective, reliable, and extremely efficient and labor saving, particularly in an industry where labor costs tend to be significant.